Professional imaging systems, such as those employed for medical diagnostic (radiological) applications, having historically captured and recorded images on relatively large sized sheets of photosensitive material, using large volume wet development equipment. With the recent enactment and more rigid enforcement of environmental regulations that require safeguards against exposure to and proper disposal of chemicals used in image development equipment, image processing providers have begun the replacement of these cumbersome and expensive wet-development systems with dry silver processes. For example, in a typical dry silver imaging application for medical diagnostic applications, such as a sonogram or X-ray, the image of interest may be electro-optically captured on a 20.3 cm.times.25.4 cm (8".times.10") sheet of dry silver photosensitive medium, so that the image size is large enough to be viewed and analyzed, is readily physically accommodated within the patient's file, and may be easily handled and stored by medical personnel without exposure to wet chemicals.
In the course of operation of a dry silver process-based imaging system, just as in the use of relatively small hand-held cameras, it is necessary to store the individual frames of the photosensitive media in a light-tight housing, while affording ready access to the frames as they are needed by the imaging equipment. In hand-held cameras, the film packaging is relatively compact, with the film being configured as either a continuous multi-frame roll housed in a light-tight cylindrical canister, or as individual sheets that may be housed in an auto-feed sealed cartridge that is disposable after all of the film sheets have been used. Unfortunately, due to their configuration and small size, neither of these hand-held camera film storage and feed approaches is capable of storing larger sheets of photosensitive material and interfacing such media with the sheet or web advance mechanisms employed by the larger, diagnostic imaging equipment.
Light-tight, single-use containers or packages for larger photosensitive materials used in, for example, medical diagnostic applications are generally known. As shown in U.S. Pat. No. 4,860,042, these light-tight containers can include a film bag or a tray covered by a lid. Also shown are carriages, or holders, which mate with the main body of a film loading device and removes the cover or the film bag while maintaining light-tightness.
In addition, there is disclosed in co-pending U.S. patent application Ser. No. 08/344,462 filed Nov. 23, 1994, entitled "Imaging Unit Container Having Shiftable Walls" a bag for storing the photosensitive sheets. The bag is sealed on three sides and has an opening through which the photosensitive sheets are placed into the bag. The open end of the bag is then rolled up and taped to the bag, thereby creating a light-tight enclosure. The bag also includes a tabbed end. However, in the process of rolling the open end to make light-tight seal, air may become entrapped within the cavity of the bag. The bag may then become bulky and later handling and shipping of the bag becomes more difficult. In a non-related field, there are bags for bulk material which include seals that are discontinuous. An example of this is shown in French patent 2,234,356. The discontinuous seal is useful in allowing air to escape from the bag so that the bags may be more easily stacked. However, this is for use in a non-analogous field as there are no provisions for providing a light-tight seal which is necessary for photosensitive materials.
The present invention addresses the drawbacks of the prior art devices and provides for a light-tight bag having a serpentine passageway at one end, thereby creating a light-tight end and also allowing for entrapped air to exit the bag.